1. Field of the Invention
The present invention relates to an apparatus and a method for a video telephony function of a portable terminal. More particularly, the present invention relates to a method and an apparatus for recovering video information in an area that impairs an electromagnetic field of a transmit/receive signal during a video telephony function of a portable terminal.
2. Description of the Related Art
Portable terminals are prevalently used without distinction of age and sex as a necessity in the modern life. Service providers and terminal manufactures are competitively developing products (or services) to distinguish their products (or services) from others.
For example, the portable terminal is advancing to a multimedia device which provides various services of a phone book, a game, a short message, an e-mail, a morning call, a Moving Picture Experts Group (MPEG) audio layer 3 (MP3), a digital camera, a wireless internet service and the like. In accordance with advances of the information communication technology including the Internet, the portable terminal provides a video telephony service as well as a text service and a voice telephony service.
For video communications, a portable terminal supporting a video telephony service captures images of a user, compresses the captured user video, and transmits the compressed video to a correspondent portable terminal. A terminal, receiving the compressed user video, recovers the original user video and displays the original user video on a display.
Hence, the users of the two portable terminals can communicate with each other while viewing the other user. In addition, the user of the portable terminal can save contents of a video call to the portable terminal during the call, or transmit video or image data stored in the portable terminal to the other user in real time.
When an error is detected in the video information through a Cyclic Redundancy Check (CRC), the video telephony service decodes the corrupted video information without discarding it and sends a Video Fast Update (VFU) signal to the other portable terminal.
The portable terminal receiving the VFU signal generates and transmits intra coded (I) frames to the other portable terminal.
However, when the portable terminal providing the video communication service is operating in an area that impairs an electromagnetic field of the transmit/receive signal, the VFU signal is transmitted until the portable terminal moves out of the area that impairs the electromagnetic field of the transmit/receive signal. In this situation, the portable terminal receiving the VFU signal needs to generate the I-frame occasionally in mid course.
In other words, while the portable terminal can block a transmission of the video information stream resulting in an error that is constituted mostly of Predicted (P) frames by decoding the video information using the I frames received through the VFU signal, a transmission resulting in an error is unavoidable in the area that impairs the electromagnetic field of the transmit/receive signal.
Therefore, what is needed is a method and an apparatus for recovering video information, according to a condition of an area that impairs an electromagnetic field of a transmit/receive signal, in a video telephony service of a portable terminal.